let isNumber: number = Number(1);
let isBoolean: boolean = Boolean(true);
let isString: string = String('你好');


let num: number = 12;
let username: string = '我的年龄'+num;
let sum: number;
sum = 123;

//任意值类型(any)
let admin:any = 'abc';
admin = 123;

function f():any {
  return admin;
}
